Effects of oral cimetidine and ranitidine on gastric pH and residual volume in children

Abstract

The effects of orally administered cimetidine 7.5 mg/kg (group 1), ranitidine 1.5 mg/kg (group 2), ranitidine 2.0 mg/kg (group 3), or a placebo (group 4) on gastric pH and gastric residual volume of 60 healthy children 2-6 yr of age admitted for elective surgery was evaluated. Both cimetidine and ranitidine administered 1-2 h prior to induction of anesthesia effectively increased the gastric pH: 5.47 ± 1.85 ml/kg (group 1), 4.92 ± 2.1 ml/kg (group 2), 5.30 ± 1.82 ml/kg (group 3) compared with 1.75 ± 0.58 ml/kg (group 4) (P < 0.001). A single dose of ranitidine 1.5 mg/kg was as effective as ranitidine 2.0 mg/kg and cimetidine 7.5 mg/kg. Neither drug decreased the gastric residual volume: 0.32 ± 0.33 ml/kg (group 1), 0.31 ± 0.06 ml/kg (group 2), 0.23 ± 0.05 ml/kg (group 3), and 0.33 ± 0.05 ml/kg (group 4). The combination of a volume > 0.4 ml/kg and a pH < 2.5 was found in 33% (five of 15) of patients in the placebo group (group 4). In contrast, there were no patients with this combination in groups 1, 2, or 3 (P < 0.001).